#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
#define rng(i,a,b) for(int i=int(a);i<int(b);i++)
#define rep(i,b) rng(i,0,b)
using ll = long long;
using ld = long double;
int main(void){
    string S;
    cin >> S;
    if(S[0] == S[1] && S[1] != S[2])cout << "Yes"s << endl;
    else cout << "No"s << endl;
}